Geographic Range

Southern pudus are native to southern Chile and southwestern Argentina. Their range occupies the space between the Maule River as the northern boundary and Chiloé province as the southern boundary. They can be found in humid temperate rainforests that occupy parts of both Chile and Argentina and along the Cordilleran coast. More southern pudus are found on Chiloé Island than on mainland Chile. Southern pudus originally ranged from 35 degrees south to 53 degrees south, but with decreasing population density. (Hershkovitz, 1982; Junge, 1966; Meier and Merino, 2007; Miller, et al., 1983)

Physical Description

Southern pudus are the second smallest deer in the world. Generally, they are larger than northern pudus (Pudu mephistophiles), and smaller than dwarf brocket (Mazama chunyi). Average height measured at the shoulder is from 35 to 45 cm and body length is short, usually not exceeding 85 cm. They typically weigh between 6.5 and 13.5 kg, with females weighing approximately 1 kg less than males. Growth rate in southern pudus is 53 grams per day until adult weight is achieved.
Southern pudus are short with short legs, the rump is not raised, which distinguishes them from other cervids. They have slender hooves with an interdigital gland enclosed in a deep pocket, a short snout, and their ears are not pointed. The tail is small and concealed; it ranges from 30 to 40 mm in length. Southern pudus have short rostra because of reduced premaxilla and nasal bones and a short diastema. Skull length ranges from approximately 134 to 155 mm, while braincase width ranges from approximately 47 to 51 mm. Zygomatic breadth ranges from approximately 64 to 70 mm. Nasal bone width has a reported range from 31 to 44 mm and the diastema measures approximately 35 to 43 mm in length.
The incisors have rectangular crowns (Traub in Jiménez 2010). The dental formula of southern pudus is not reported but other members of the Family Cervidae have the following formula: I 0/3, C 0/1, P 3/3, M 3/3 = 32. Cervids typically lack one premolar in both their deciduous and adult set of teeth. The upper canine is sometimes present in fawns, but is not present in adults. (Bonacic, et al., 2003; Bubenik, et al., 2000; Clarke, et al., 2010; Hershkovitz, 1982; Hick, 1969; Jarman, 1983; Jiménez, 2010; Junge, 1966; Meyer, et al., 2008; Pontier, et al., 1989; Reyes, et al., 1993; Ziegler, 1971)

Besides a slightly larger mass and small antlers on males, there is limited sexual dimorphism between males and females as both sexes have similar height and appearance and reach their adult weight at approximately the same time early in life. The appearance of the glans penis on males is similar to that of Odocoileus species.
Southern pudu fur color is a dark red-brown and the hue varies between individuals and between seasons. The fur is strong and stiff but sparse with approximately 800 to 2500 hairs per square cm on the trunk. Individual hairs are long and characteristically hollow. Juveniles show three rows of lighter spots on their dorsal surface that are lost by the age of 8 weeks. Southern pudus shed their fur in both the spring and in the fall and it was reported that fur color in captive species became darker after the September molt. Northern pudus (Pudu mephistophiles) are smaller, with shorter legs and have dark brown to black color on the ears, chin, face, forefeet, and hindfeet whereas southern pudus are larger, brown with red markings on the ears and chin. Southern pudus have visible preorbital glands, while northern pudus do not. The preorbital gland is large with a wide opening on the rostrum. These glands are not as visible on female southern pudus.
The antlers of males are very small (between 60 and 90 mm). Antlers first form on young males between the ages of 9 to 12 months. New antler growth occurs mostly in July, which correlates with decreased levels of leutinizing hormone (LH) and testosterone. The antlers mature and are polished by November as LH and testosterone levels start to rise again, and are shed in the austral summer months. Females do not produce antlers. At some latitudes, pudus shed the velvet of the antlers.
Southern pudus living at higher latitudes have a higher metabolic rate and higher levels of triiodothyronine. A specific metabolic rate for the southern pudu is not yet reported, but artiodactyls have relatively high metabolic rates compared to other mammalian orders. (Bonacic, et al., 2003; Bubenik, et al., 2000; Clarke, et al., 2010; Hershkovitz, 1982; Hick, 1969; Jarman, 1983; Jiménez, 2010; Junge, 1966; Pontier, et al., 1989; Reyes, et al., 1993; Ziegler, 1971)

Reproduction

Because southern pudus are elusive and cryptic, most of what is know about the reproduction and mating system has been learned via captive animals. Southern pudus have a polygynous mating system.
In wild populations, southern pudus form pair bonds in the fall and mate. The male is attracted to a female in estrus and will approach the female in a low, slow crouch. After the male judges the female’s responsiveness by sniffing and licking, they proceed to engage in butting the groin or sides, followed by grooming. For a three-day period, the male mounts the doe repeatedly and intercourse occurs for two to three seconds each time. (Hershkovitz, 1982; Reyes, et al., 1993)

The mating season occurs from April to June and gestation lasts approximately 7 months. Female southern pudus may employ delayed implantation. The exact length of gestation is debatable. One researcher noted that it lasts between 203 and 223 days, while another claims it can be between 197 and 223 days. This is a very long gestation when compared with other, heavier deer. Most fawns are born in austral spring, between November and January.
Females have one fawn per year, though it is not uncommon for her to have twins. Over the female’s entire lifespan, the mean number of offspring is 3.88 fawns.
Southern pudus are seasonally polyestrous breeder with a cycle lasting approximately 11 days (Vidal et al. 2012). Cycle length is variable and responsive to seasonal and environmental cues, particularly photoperiod and food quality. Males exhibit peak levels of various reproductive hormones at different times of the year. One study indicated that follicle-stimulating hormone and testosterone peaked twice within a single year. The peaks are suggested to be associated with antler mineralization and rutting behavior. Another study suggests that it is luteinizing hormone and testosterone that have two annual peaks, while follicle stimulating hormone and prolactin have only one peak. An endocrine study performed in 1993 found that testosterone and leutenizing hormone had one peak level in March, during the rut. Furthermore, spermatogenesis increases substantially only during the mating ruts, though it lasts for several months afterwards. Males are fertile approximately 7 months of the year. There is also an increase in testes size during these peaks. There are two peaks of cortisol levels in male pudu that are likely associated with elevated stress levels; one peak during the rut and the other in August. Southern pudus can breed twice per year. If a female does not become pregnant between April and June, she can ovulate again between November and January when males reach their second peak of reproductive hormones. Further research is required to understand the regulation of such a breeding pattern. (Bubenik, et al., 2000; Hershkovitz, 1982; Hick, 1969; Jiménez, 2010; Reyes, et al., 1993; Vidal, et al., 2012)

Most of what is known about parental investment in southern pudus was studied in captive animals. Young are born precocial, with their eyes open, and are able to stand after birth. When they are born, fawns are approximately 20 cm in height and weigh less than 1 kg (Jiménez 2010). The female parent cares entirely for her offspring. The female ingests the afterbirth and licks the offspring clean. She attempts to stimulate urination and defecation in the infant. The mother allows her infant to suckle within an hour after birth. The female’s milk is composed of fat, albumin, lactose and high quantities of sodium and potassium. Under captive conditions, when an infant would bleat, the mother rushed to her offspring and allowed nursing. According to one study, a fawn was last seen suckling at 30 days old, but when the fawn attempted to suckle at 60 days old, it was rejected by the mother. Another study states that the weaning age is 1.8 months, at an approximate weight of 3 kg. Young fawns become independent from their parents at approximately 8 months old. Young southern pudus must establish a new home range away from their parents due to their solitary nature. (Eldridge, et al., 1987; Hershkovitz, 1982; Hick, 1969; Jiménez, 2010; Lee, et al., 1991; Vidal, et al., 2012)

Lifespan/Longevity

The longest lifespan in captivity was measured at 17.9 years in the Rotterdam Zoo, though the expected lifespan in captivity is between 4.35 and 17.4 years for females and between 4.44 and 15.8 for males. Mortality within the first month of life is 26%, for both males and females. (Jiménez, 2010; Weigl, 2005)

Behavior

Southern pudus show relatively high levels of daily activity. They are active both during the day and night. They tend to rest and groom during the middle of the day and are active during the late afternoon, evening, and morning. Southern pudus exhibit play behavior; they skip, run and playfully fight with each other. They groom themselves by licking their fur and combing their fur it with their incisors. They rub their antlers and scrape their teeth on trees and some plants.
Weather appears to play a role in their activity levels. Southern pudus shows more activity on windy days rather than calm days, an indicator of their intolerance to heat. Though not solitary, southern pudus appear to move together when feeding, but do not form groups larger than 2 or 3. However, most of the time, southern pudus are solitary, cryptic, and sedentary. Southern pudus can easily adapt to many temperature zones in which other deer can live, as demonstrated by their behavior in captivity. When exposed to prolonged cold during the spring and summer months of the southern hemisphere, southern pudus have a seasonal peak in triiodothyronine, as it adjusts its metabolic rate.

Most of what is known about southern pudu hierarchy systems was gathered from captive animals. They form dominance hierarchies and are highly territorial. The hierarchy usually includes one dominant male, followed by subordinate males then juvenile males, with females as the most subordinate. A hierarchy exists among females as well. Dominant pudu males have higher levels of insulin-like growth factor and testosterone compared to subordinate bucks. If two males of similar size encounter one another, it often results in a fight. A male pudu will fight and kill an intruder of the same sex.

Southern pudus use submissive postures when frightened, exhausted or in the presence of dominant animals; laying down completely flat with the neck horizontal and extended, crouching with the tail down, or lowering the neck and avoiding eye contact while standing. Southern pudus can also show aggressive postures; pointing their antlers at an opponent, standing still near the opponent with the snout raised in the air, or with the head low as if preparing to butt the opponent. They use a broadside display, where the animal arches their back and shifts their weight to the hind limbs, the tail is held horizontal, the preorbital glands throb and their ears are erect. A dominant pudu will chase a submissive pudu until exhaustion while attempting to hit the opponent with their forelimbs or attempting to bite the opponent.
Home range size is variable among southern pudus and has been recorded in one study as being from 16 to 26.1 hectares in size. Another study showed home ranges that varied from 2 to 200 hectares (Ramilo in Jiménez 2010). (Bubenik, et al., 2000; Cortés, et al., 1988; Eldridge, et al., 1987; Hershkovitz, 1982; Hick, 1969; Junge, 1966; Macnamara and Eldridge, 1987)

Home Range

Home range is variable among southern pudus and has been recorded in one study as being from 16 to 26.1 hectares in size. Another study showed home ranges that varied from 2 to 200 hectares (Ramilo in Jiménez 2010). (Eldridge, et al., 1987; Jiménez, 2010)

Communication and Perception

Southern pudus rely heavily on olfaction as a means of foraging and investigating. They sample the environment by sniffing, chewing and licking objects around them. Afterwards, they exhibit a flehmen response. They have large preorbital glands in deep lacrimal fossa and southern pudus mark an object by rubbing their gland against it. This can occur during a dominance display, courtship ritual, or when they are stressed. Southern pudus potentially use elimination postures as a form of communication. Males and females each have different postures when urinating or defecating, both serve to spread their scent. In captive species, a urinating female pudu will attract a male pudu and he will lick and smell the female. Pudus can also leave their scent by antler rubbing. (Jiménez, 2010; Macnamara and Eldridge, 1987)

Food Habits

Southern pudus use a network of trails to move to feeding areas throughout the day. They prefer to eat at the edges of forests or clearings where there are abundant small, growing plants, rather than deep within the forest. They are highly selective in what they eat. They are browser feeders and feed on leaves of ferns, trees, vines, herbs and shrubs. They can stand on the hind legs or fallen logs to reach food. Their competitors include other herbivores: European roe deer (Capreolus capreolus), fallow deer (Dama dama) and European hares (Lepus europaeus). Southern pudus are ruminants, with four-chambered stomachs. The mean transit time of a meal is approximately 29.9 hours. In captivity, southern pudus eat a wide variety of fruit, vegetables and fungi. Plant foods include: Gevuina avellana, Fuschia magellanica, Ugni molinae, Berberis buxifolia, Crinodendron bookerianum, Pernettya pumila, Azala species, Nothofagus species ferns, tree foliage, vines, herbs, shrubs, twigs, buds, berries, fruit, roses, plantain, and clover. Other types of foods include: alfalfa hay, cereal, and vegetables, acorns, nuts, and salt. (Conklin-Brittain and Dierenfeld, 1996; Eldridge, et al., 1987; Henning, et al., 2011; Hershkovitz, 1982; Jiménez, 2010; Macnamara and Eldridge, 1987)

Predation

The main natural predators of southern pudus main are pumas (Puma concolor). Southern pudus are one of the most important prey for Chilean pumas. Other predators include foxes (Dusicyon grisseus), spotted cats (Felis guigna and Felis colocolo), kod-kods (Leopardus guigna), domestic dogs (Canis familiaris), and owls (Bubo bubo). There has been an increase in the number of domestic dogs (Canis familiaris) in the range of southern pudus, increasing the instances of attack and death of pudus. Domestic dogs also interfere in the success of southern pudus via increased disease transmission and resource competition. To flee from predators, southern pudus hide in small tunnels or burrows. Because pudus tire quickly, there is little likelihood of them evading a chasing domestic dog. (Eldridge, et al., 1987; Henning, et al., 2011; Hershkovitz, 1982; Jiménez, 2010; Junge, 1966; Rau and Jiménez, 2002; Silva-Rodríguez and Sieving, 2012)

Ecosystem Roles

Several parasites have been reported, including gastrointestinal nematodes, lice, flies, and ticks. Reported parasites include Sarcosystis species, Trichostrongylus axei, Oesophagostomun venulosum, Ostertagia species, Cooperia species, Nematodirus species, Cysticerces teniucollis, Linguatula serrata, Ixodes taglei, Ixodes stilesi.
Southern pudus carry lice, including the species Bovicola caprae and Solenopotes binipilosus were discovered on pudus in one study. The appearance of lice on southern pudus is thought to be an accidental transmission from nearby goats.

Because southern pudus are herbivores and browsers, they impact vegetation abundance, consumption and growth. They can modify abundance of a particular tree species, and also facilitate spreading of seedlings. This could be harmful if the seedlings being distributed were from an introduced plant or tree species. If southern pudus prefer eating native species of plants and trees, this offers an opportunity for invasive species to infiltrate further as their competition is decreased. One study focused on how non-native deer influenced the spread of invasive vegetation, but additional research is needed to understand what impact southern pudu diet has on native and non-native vegetation.

Economic Importance for Humans: Positive

Southern pudus are used in the pet industry and in zoos in South America, North America, and Europe. There are reports of southern pudus being hunted for meat and fur, and skins being traded, both legally and illegally. (Hershkovitz, 1982; Iriarte, et al., 1997)

Economic Importance for Humans: Negative

Because pumas (Puma concolor) subsist mainly on southern pudus, declining pudu populations cause a bottom-up effect in the trophic scale and may affect ecosystems as pumas shift their diet to other prey. Southern pudus carry several ecto and endoparasites that are transmissable to humans, including gastrointestinal nematodes, lice, ticks, and flies. There are reports that southern pudus contract and die from disease, though little research has been conducted. For example, foot and mouth disease, poxvirus infection, bacterial infections, and bovine pestevirus have all been reported in southern pudus. There is a published report of a southern pudu dying from Arcanobacterium pyogenes septicemia. These diseases could have adverse effects on the populations of people who eat pudu meat. (González-Acuña, et al., 2004; Hershkovitz, 1982; Jiménez, 2010; Junge, et al., 2000; Twomey, et al., 2010)

An invasive species of deer, chital (Axis axis), introduced into Argentina in 1906, competes with southern pudus for resources and displaces them. Another cervid species, elk or red deer Cervus elaphus, was introduced in the early 20th century and has caused damaging effects on forest and vegetation within the southern pudu range. Because of their declining populations, captive breeding programs were established at state parks and at the University of Concepcion. In 1994-1995, 23 establishments in Chile had captive breeding programs for southern pudus. Several strategies have been suggested to maintain pudu populations, monitor their population size, understand their threats and pressures and eliminate or control those specific threats. For example, a feral dog management plan within pudu ranges would likely assist in the conservation of pudu populations. (Bubenik, et al., 2000; Eldridge, et al., 1987; Hershkovitz, 1982; Iriarte, et al., 1997; Jiménez, 2010; Novillo and Ojeda, 2008; Silva-Rodríguez, et al., 2011)

Contributors

Meagan Robidoux (author), University of Manitoba, Jane Waterman (editor), University of Manitoba, Tanya Dewey (editor), University of Michigan-Ann Arbor.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

causes disease in humans

an animal which directly causes disease in humans. For example, diseases caused by infection of filarial nematodes (elephantiasis and river blindness).

causes or carries domestic animal disease

either directly causes, or indirectly transmits, a disease to a domestic animal

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

delayed implantation

in mammals, a condition in which a fertilized egg reaches the uterus but delays its implantation in the uterine lining, sometimes for several months.

dominance hierarchies

ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

folivore

an animal that mainly eats leaves.

food

A substance that provides both nutrients and energy to a living thing.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

polygynous

having more than one female as a mate at one time

polymorphic

"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic.
Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

sexual ornamentation

one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.

solitary

lives alone

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

young precocial

young are relatively well-developed when born

References

Bonacic, C., J. Riveros, F. Bas. 2003. Herbivores in the agro-ecosystems of Latin America. Proceedings of the VI International Symposium on the Nutrition of Herbivores: 1-23.

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The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

This material is based upon work supported by the
National Science Foundation
Grants DRL 0089283, DRL 0628151, DUE 0633095, DRL 0918590, and DUE 1122742. Additional support has come from the Marisla Foundation, UM College of Literature, Science, and the Arts, Museum of Zoology, and Information and Technology Services.